O2 Sensor

[dreaminbohemian]

I purchased my truck from Pete Rushbrook Cruiser54 back in November.  I had started asking him about it in February but we didn't finish our chat before I hit the road for work. I ran into some trouble and upon inspection the 02 sensor being run is stamped with 1247.  It has three wires coming out of the sensor, Red, White, and yellow, then white and yellow are soldered together to a black wire.  My loom was ripped off when my speedo cable broke, wrapped around the forward drive shaft and shredded everything.  There was no plug left on the o2 sensor.  I am curious:
1)Is this a fine 02 sensor to use? I can't find anything on it but 1247 which looks like a GM part but I struggle to find clear info.
2)Do I make it 3 wire again? What pins do the red white and yellow got to?

[dreaminbohemian]

I have just realized that the 4th wire may have been pulled out.  There is a hole for a 4th wire in the back of the sensor but I assumed that they used the same plug for three and four wire variants

[Htchevyii]

This is on the 87? It should be a 3 wire unless its been swapped to a wideband sensor controlled by a Nick in time designs REM.

 

https://nickintimedesign.com/rem-wideband-converter/

 

 

 

[dreaminbohemian]

Looks like most all of the current ‘fitting’ o2 sensors that  are produced  are 4 wire sensors wired to a 3 sensor plug. I have found repeated reports across several forums